Mechanical pencil



Mad 24, C. WAHL MECHANICAL PENCIL Original Filed June 14, 1924 Patented Mar'. 24, 1931 UNITED STATES `PATENT OFFICE JOHN C. WAHL, 0F CHICAGO, ILLINOIS, ASSIGNOB T0 THE WAHL COMPANY, 02E CHICAGO, ILLINOIS, A/CORPORATION 0F DELAWARE MECHANICAL PENCIL Application filed inne 14, 1924, Serial No. 719,479. Renewed December 21,1926.`

This invention relates to mechanical pencils and more particularly to mechanical pencils embodying improved means for permitting the lead propelling mechanism of the pencil to be withdrawn from the pencil by a direct rearward pull when the lead has become exhausted and only at such time.

In particular, the invention herein involves certain improvements in the constructional details and mode of operation over the construction disclosed in my co-pending application, Serial No. 664,896, iled September 26, 1923, which has since matured into Patent No. 1,729,142 issued September 24, 1929. In my prior application the lead propelling mechanism, which is housed in the usual pencilA casing, is provided with a crosshead having a threaded surface adapted to engage inner threads on the wall of the pencil. casing so that when the propelling mechanism is rotated relatively to the casing, the crosshead will be progressed toward the tip of the pencilI and will serve to gradually feed the leads through the pencil tip.

Mounted Within the lead propelling mechanism is a channel member which serves to normally maintain the crosshead in threaded engagement with the threaded wall of the casing so that the lead propelling mechanism is in engagement. This member is provided at its forward end, that is the end toward the lead tip of the pencil, with an aperture which is positioned in the path of movement of the gradually advancing crosshead so that when the crosshead arrives at an extreme forward or advanced position it will enter the aperture in the member and thus release the crosshead from engagement with the threaded wall of the pencil casing. This constitutes the releasing means to permit the lead propelling mechanism of the pencil to be entirely withdrawn rearwardly from the pencil casing. In order to prevent this automatic disengagement from occurring at any other position of the crosshead than the position corresponding to that in which the lead is exhausted, the apertured member is mounted for shifting movement so as to displace the aperture therein from that position in which it normally functions to release the lead propelling mechanism as heretofore described. For instance, it is at times desirablev to withdraw the lead propelling mechanism a short distance in order to permit -access to the lead holding chamber at the rear of .the

lead propelling mechanism. In this position of the lead propelling mechanism it is not desired to bring about the disengagement of the crosshead from the threads on the inner wall of the casing. If the apertured member 50 before mentioned -were not provided with means to dislocate the aperture therein when thelead propelling mechanism was so retracted, the aperture would register with the crosshead and bring about such undesired 05 disengagement. And in order to prevent this my prior mentioned application disclosed a simple construction wherein the apertured l member was provided with projections or pimples upon its inner walls, which pimples lay in the path of movement of the crosshead so that as the latter passed by it pressed against these pimples and dragged or carried the apertured member with it and thereby displaced the aperture fromv its normal registering position.

One of the main features of the present invention resides in providing a construction wherein a p-ositive shifting of the apertured member is assured; a construction `wherein the member is positively shifted no matter how many times it has been used.

- Another feature of the present invention resides in providing a more simple construction of apertured member wherein the assembling of the member within the lead propelling mechanism is more easily effected and wherein the member itself and the lead propelling mechanism can be m-ore cheaply and easily manufactured and assembled.

Additional features of the invention comprehend the construction of the apertured member and the construction of lthat portion of the lead propelling mechanism into which the member litsV and is shiftably mounted o5 wise `movement therein. An ancillar v feature of this particular portion ofthe invention consists in the lost motion connection between the members of the lead propelling mechanism, whereby the members may be relatively shifted a predetermined amount.

Still another feature of the invention resides in the beveled construction of the portion of the vcrosshead which is adapted to re'gister with ,the aperture in the member. This beveled formation of the crosshead assists in the registration of the crosshead and the aperture and also assists in the ejection of the crosshead from the aperture after the release has taken place.

These and other features of the invention will be apparent from a perusal of the speciication when taken in connection with the accompanying drawing wherein:

Fig.' 1 is a sectional elevation of my improved pencil, showing the lead propelling mechanism and particularly the crosshead in its rearward position.

Fig. 2 is an elevatonal view of the pencil partly in section, showing the lead propelling mechanism at the extreme advance of its movement, which corresponds to the lead eX- hausted condition of the pencil.

Fig. 3 is a fragmentary view of a pencil in section corresponding partly to Fig. 1, except that the actuator or lead propelling mechanism has been partiall withdrawn to expose the lead storage cham er. In this view the crosshead is in threaded engagement with the inner thread on the pencil casing.

Fig. 4 is a detailed sectional view showing the lead propelling mechanism detached, a portion of the lead propelling mechanism eing broken away.

Fig. 5 is a perspective view of the apertured member,'and,

Fig. 6 is a section taken on line 6-6 of Fig. 1.

Referring now to the drawings in detail, the pencil comprises an outer barrel or casing 1 provided at its outer end withthe usual l lead tip 1 the features of which form no part of the present invention and therefore are not described in detail. The casing is provided with an inner tube or lining 2 secured therein by the crimping 3. This tube or lining 2 is provided with an inner roll thread 4 which extends longitudinally thereof for a considerable proportion of its length, and finally terminates in a sleeve portion forming a conical holder 5, anda smaller sleeve 6 terminating in a lead holding sleeve 7. This sleeve 7 is threaded on its outer ends to receive the shank of the pencil tip 1 as is well known in the art. The opposite end of the casing 1 terminates at point B and is open to receive the lead propelling mechanism now to be described. v

The lead propelling mechanism is principally in the form of a tube 8, hereinafter called an actuator, rwhich tube is formed at its upper end with a hollow chamber 9 ada ted to house and receive the spare leads 10 fbi thepencil. A washer 11 forms one end of this chamber 9. That portion of tube 8 which extends forwardly of the washer 11 is formed with an open end. This portion of the tube is provided with a closed slot 12 which extends from a point 13 to a point removed from the front edge of the tube so as to form a cross piece or stop- 14, the consequence of which will be hereinafter made evident. Free ledges of the slot 12 are curled inwardly to form guide flanges l15 for the crosshead. The

--inner portion of the, tube 8 is thus formed hollow to house or receive an apertured member which forms one of the main features of this invention.

As "seen clearly in Fig. 5', this apertured member 16 is rather long so as to extend within the tube 8 substantially the length of the forward portion thereof. It is open at one end, vand at the other end is swedged down to yform a conical shoulder 18 and a rather small sleeve 19, adapted to form .that portion of the apertured member which fits within the similarly formed sleeve 6 of the tube 2. Apertured member 16 is provided with slot 17 extending from its open end to a point slightly removed from the shoulder 18. This slot 17 registers with the slot 12 in the tube 8 so as to permit the crosshead to pass therethrough when the apertured member 16 is housed within the tube 8. In addition, that portion of the apertured member opposite the slot 17 is provided with an aperture 20. This aperture 20 is positioned adjacent the shoulder 18 and at such a position that when the member 16 is in extreme advanced position and when the crosshead hereinafter referred to is in its corresponding position, the crosshead and the aperture 2() will register, as will be hereinafter made evident. The crosshead, except for a beveled portion thereof, which will be hereinafter described, is similar to that disclosed in my afore mentioned application. This crosshead 21 is provided with a threaded portion 22 and with lateral shoulders 23 and 24, which shoulders engage the folded over edges 15 of the walls of the slot 12 of tube 8. This threaded portion 22 of the crosshead has a lower notch or shoulder 22a below the lower thread fora purpose to be hereinafter described. That portion of the crosshead 21 which is opposite the threaded portion 22 is suitably shaped to register with and sink into the aperture 2O of member 16. In order to assist this portion of the crosshead 21, which is now designated as 25, to its registering position, such portion is provided with a bevel 26 so that as the crosshead approaches the aperture 20, the bevel will assist the crosshead in finding this aperture and conversely after the crosshead has been receivedin the aperture 20 and it is desired to eject the same therefrom, it will be manifest that the bevel will permit the crosshead to ride easily out of aperture 20. The forward portion of the crosshead 21 is provided with a plunger 27 preferably in the form of a Wire or rod. This plunger 27 constitutes the lead propelling plunger. Its forward end engages the lead 10 and pushes it to the tip 1 as is well known in the art. It will be noted from the foregoing construction that this construction lends itself to an easy assembling of the member 16, the tube 8 and the crosshead 21. This is due to the fact that the tube 8 is formed with an open end and that the slot 17 `is formed in the member 16 so that the crosshead 21 can be placed within the slot 12 of member 8 by passing it angularly through the open end of member 8, and then passing the open end of member 16 into the open end of member 8 with slots 12 and 17 in proper registry.

Means is provided for shifting the member 16 longitudinally within the tube 8. To this end the member 16 is provided with a closedended slot 27 which is adapted to engage with a lug or pin 2,8 formed by a dent in the wall of tube 8. This constitutes a lost motion connection between the Amember 16 and the tube 8. Resilient means is provided for producing a positive displacement of the member 16 relative to its enclosing tube 8. In the particular form illustrated, this means comprises a coil spring 29 which is arrangedaround the plunger 27 and housedv within the tapered or conical end 18 of the memberl. As thus located, when the crosshead 1s brought toward the conical shoulder portion 18 of the member, the spring will be ut under compression and if the member is ree to move the member will accordingly be advanced by the compression ofthe spring toward the tip or front of the pencil. This advancing movement of the member 16 willdisplace the aperture 20 so that it will not come into registry with the beveled portion 26 of the crosshead 21, and there will be no releasing movement of the thread 22 from the thread 4 on the inner wall ofthe casing ,2, until the crosshead reaches its furthermost position of advanced travel as illustrated in Figure 2.

As shown clearly in Figure 4, the`outer end of the tube 8 is provided with a thread'30 upon Which screws a sleeve 31 provided with an end cap or washer 32 adapted to form a seat for the eraser 33. This washer 32, in addition, constitutes a. closure for the end of the lead chamber 9. Inasmuch as this construction is claimed in the co-pending application filed by me on September 26, 1923, Serial No. 664,896, no claim thereto will be made in this patent application. A cap 34 frictionally fits over the sleeve 31l and forms an end cap or turningmember for the actuating tube'8.-

Describing the operation of 'a pencll con-v is, in its forward position within the conical shoulder 5 of the tube 2, and the lead holding sleeve 19 of the memberl is also ositioned in the corresponding sleeve 6 -o the tube 2. The spring 29 is shown as lying in the forward position of the member surrounding the wire or plunger 27. If now the actuator tube 8 is rotated relatively to the casing l to propel the lead forwardly to the tip as is well known, the crosshead 21 .Will advance until it contacts with spring 29 and will thereupon compress it as shown in Fig. 2. As the crosshead continues on it will inditself in the slot 20, thereby permitting the crosshead to move bodily laterally within the sleeve 16 to disengage the thread 22 on the crosshead from the thread 4 on the inner wall of the casing 1. This constitutes the releasing position or thread disenga-gingV position of the crosshead with respect to the casing and is then in the position of the leadpropelling mechanism corresponding to the ezhausted condition of the lead in `the casing 2. When the releasing occurs the lead propelling mechanism may be withdrawn bodily from the casing l by a direct longitudinal pull, that is, without rotat- Y in-g or unscrewing the crosshead`l relatively from the casing. Upon the initial movement of the lead propelling mechanism, i.' e., during the lost motions thereof, the tube 8 of the same will move relatively to the member 16,l at which time the cross piece o r stop 14 will engage in the notch or shoulder 22a in the lower edge of the threaded part of the cross head 21 to retain this cross head in the slot .26 during subsequent longitudinal movement of the mechanism and for withdrawal of the same from the casing 1. When the propelling mechanism is in the position indicated in Fig. 1, it is sometimes desirable to retract the lead propelling mechanism in order to have access to the lead within the lead chamber 9 of the tube 8 or fo-r other purposes such as to ascertain the length of usable leadrstill inthe pencil,'etc. At this time it is not desired to have the crosshead 21 disengage from threaded connection with the casing 1, and

therefore it is not desirable to have the slot 20 abreast of thecrosshead. The mechanism hereinbefore described will prevent this disengagement and in the following way. When the actuator tube 8 is withdrawn the member 16 will likewise be retracted and this retraction of the member 16 .and actuator tube 8 will continue until the cross bar 14 of the tube 8 contacts with the crosshead 21. During this retraction of the member 16 the conical shoulder- 18 thereof forces the forward end ot' the spring 29 against the crosshead 21. At this point the spring will becompressed and will therefore force the member 16 Jforwardly relatively to the tube 8, a distance which will be the length of the slot 27', such lost motion vconnection i'iermitting this relative shifting.

This advancing movement of the member 16 relative to the'actuator'tube 8 will displace the aperture 20 in the member 16 relative to the' forward position ofthe crosshead 21 asl shown in 3. Accordingly, there .will be no registration of the crosshead 21 and the aperture 20 and, therefore, no release of the lead propelling mechanism. When the actuator tube is returned to advanced position,

that is, to the position shown in FigQl, the- AIt will, of course, be understood` that the v various details of construction hereinafter-described are merely illustrativeof the broad features of the invention and the invention isl not to be lconstrued or interpreted as being limited thereby.

Having thus claim: i

1. In a mechanical pencil, the combination of a casing having a tip and an interiorly described my invention, I

threaded portion, an actuator including a threaded crosshead adapted to engage said threaded portion to propel a lead through the tip upon rotation of said actuator, a member longitudinally slidable in said actuator, said member having an opening to register with a portion of said erosshead at a predetermined position of said member and crosshead to permit release of the` crosshead from the threaded portion, and a spring interposed between said crosshead and said member to prevent registration of said portion of the crosshead and opening except when the crosshead is at the forward limit of its movement in said easing.

2. In a mechanical pencil, the combination of a casing having a tip and a threaded inner wall, a lead propelling mechanism including a crosshead having a threaded portion engaging said threaded wall and adapted onv operation of said actuator to propel the lead through the tip, and a member having an aperture adapted in a predetermined position of said crosshead and member to register with said crosshead topermit the release of said crosshead from said threaded portion and spring means constructed and arranged to \\with an aperture adapted to register with ,l

said crosshead at a predetermined position of said member and crosshead -to permit the relealsleof said crosshead from said threaded wa l '4. In a mechanical pencil, the combina- 'tion of a casing having a tip, anactuator lhoused in vsaid casing and provided with 'means for operatively engaging said casing to provide forj the propulsion of the lead through the tip,a member shiftably mounted with respect to said actuator and provided with an aperture adaptedl to register with the casing engaging portion of said actuator to permit their release, means to shift the member in one direction and a spring to shift the member in the other direction to prevent registration of said aperture and means.

5.v In a mechanical pencil, the combination of a casing having a tip, an actuato: housed insaid easing and provided with means -for operatively engaging the casing to propel the lead through the tip, a member shiftably mounted with respect to said actuator and provided with an aperture adapted to re ster with said means to permit the release o said means from said casing, a 10st motion connection between said member and said actuator and a spring to prevent the registration of said aperture and means except at a predetermined positionthereof. v

, 6. In a mechanical pencil, the combination of a casing having a tip, an actuator housed 1in said casing and provided with means for operatively engaging the casing to'propel the lead through the tip, a member slidable with the actuator, a spring housed within said member in position to engage themeans on said actuator whereby to shift said. member on a redetermined relative movement of said mem er and actuator, said member having an aperture therein adapted to register with said means at another predetermined position of said member and actuator.

7. In a mechanical pencil, the combination of a casing having a tip, alead propelling mechanism housed in said casing and provided with means operatively engagingsaid casing to propel the lead through the tip, a

member slidable with respect to said mechanism and provided with means for releasing said operative connection between said casing and propelling mechanism, means to positively shift said member and spring means operative to shift said member at a predetermined position of said member and propelling mechanism to prevent the release of said operative connection.

8. In a mechanical pencil, the combination of a casing having a tip, a lead propelling mechanism housed therein and provided with means operatively engaging said casing to propel the lead through the tip, said mechanism being formed as an open-ended tube. a member telescopingly slidable within said tube and provided With a means for releasing saidv operative connectio-n between said casing and propelling mechanism, means to positively shift said member and spring means operative to shift said member at a predetermined position of said member and propelling mechanism to prevent the release of said operative connection.

9. In a mechanical pencil, the combination of a 'casing having a tip, a threaded portion and an abutment, an actuator housed therein and provided with means to operativelyengage said threaded portion to propel a lead through the tip, a member shiftable relatively to said actuator and provided with a shoulder adapted to engage said abutment, a lost motion connection between said member and actuator, said member having an aperture adapted to register with said means and a spring carried by said member and disposed against said shoulder and in the path of said means for shifting said member on contact of said spring and means.

10. In a mechanical pencil, the combination of a casing having a threaded portion, an actuator housed therein, a crosshead slidable with respect to said actuator and rotatable therewith, a lead feedingplunger carried by said crosshead, a member telesc-opingly slidable in said actuator, `a slot and pin connection between said member and actuator,

said member having an aperture to permit the lateral movement of' said crosshead and -means to shift said member to'carry the aperture out of registering position with said crosshead. 11.A In a mechanical pencil, the combination of al casing having aninner threaded wall, a conical shoulder terminating in a guide sleeve connecting with a tip, an actuator tube rotatably housed in said casing and having its wallsjlongitudinally slotted to provide a crosshead guide, a crossheadslidably mounted in said'guide 'and engaging the threaded Wall of said casing, alead feeding plunger carried lby saidlcrosshead to project through said casing sleeve, a tube-like mem- 1 ber t'elescopingly slidable in said actuator tubeand formed with slotted Walls to permit the engagement of the crosshead with .the

casing wall, the outer end of said member having a conical shoulder terminating in a sleeve, both shoulder and sleeve adapted to nest within the corresponding shoulder and sleeve of said casing in a predetermined position of said actuator and casing, a slot and pm connection between said actuator tube and sleeve, said member having an aperture adapted to register with the crosshead on a predetermined position of said crosshead and member and a spring housed within the conical shoulder of said member and about said lead feeding plunger to lie in the path of said crosshead whereby to shift said member away from said crosshead. k

lf2. A mechanical pencil comprising a casing having an inner threaded wall and a tip, an open-ended actuator tube housed in said casing and having its Walls longitudinally slotted and curled inwardly to provide a guideway, a tubular member slidable into said actuator'tube and formed with a longitudinal slot the edge walls ,of which are adapted to lie behind said curled edges, a crosshead carried in and having a threaded portion projecting through said slots in said actuator tube and member and engaging the threaded walls of said casing, said member being provided with an aperture for causing the disengagement of said crosshead and casing at a predetermined time.

13. In a mechanical pencil, the combination of a casing having a tip and a threaded portion, an actuator housed in said casing and provided with a crosshead, a lead feeding plunger movable relative to said actuator, said crosshead having a Ythreaded portion adapted to operatively engage the threaded wall of said casing, a member carried by said actuator and provided with an aperture adapted to register with said crosshead to permit the lateral movement of said crosshead to release it from threaded engagement with said casing, and said crosshead having a beveled shoulder to assist in the registration with said aperture.

14. In a mechanical pencil, a casing having an internal threaded portion, a lead propelling actuator, a crosshead slidably mounted in said actuator and adapted to operatively engage the threads in said threaded portion, said actuator having an aperture for the release of said crosshead from operative engagement with said threads at a predetermined point of travel of the crosshead, and

spring means for positively pushing the-corsaid threads, and a resilient member for normally pushing the crosshead and release member relatively away from release position.

16. In a. mechanical encil, a casing, lead propelling mechanism 1n operative engagement with said casing, said mechanism having an aperture for releasing the same from said operative engagement, and a spring for preventing release of said propelling mechanism except at a predetermined point of travel thereof.

I7. In a mechanical pencil, a casing, lead propelling mechanism in said casing and in operative engagement therewith, said mechanism comprising a crosshead normally in engagement with said casing and a slidable release member for releasing said' crosshead from said engagement, and a spring interposed between said crosshead and release member for prevent-ing release of said crosshead except at a predeterminedpoint of travel thereof.

1 8. In a mechanical pencil, a threaded casing, lead propelling mechanism in saidv casing and in operative engagement therewith, said mechanism comprising a crosshead in threaded engagement with said casing and a slidable release member for releasing said crosshead fiom said threaded engagement, and a spring for preventing release of said crosshead except at a predetermined point of travel thereof.

19. In a mechanical pencil, a casing, lead propelling mechanism in said casing and in.

operative engagement therewith, said mechanism including a sliding spring controlled release member adapted to hold said mecha-v nism'in engagement with said casing du'rn a portion of its travel and to release -sai mechanism from said engagement at a predetermined point of travel thereof.

In witnessY whereof, I hereunto subscribe my name to this specification. f

- JOHN C. WAI-ll. 

